He's Frank Sinatra with lyrics by Jean-Paul Sartre, a sonorous crooner with an existential bent. An American, he was once massively successful as an expat in the U.K. as one-third of the Walker Brothers, who were neither surnamed Walker nor were they brothers. At the height of their fame in the mid-1960s, he turned his back on teen-idol worship to concentrate on his own idiosyncratic vision, which came to into focus with a series of four luminous, much-loved self-titled albums released 30 years ago. If the name Scott Walker is not immediately familiar, it's because the former Noel Scott Engle has long been a recluse both artistically and personally.

Walker's image - the sunglasses, the casually tossed scarf, the smoldering good looks, the oft-cited moodiness - has only heightened curiosity about an artist whose influence has been widely felt on David Bowie, Nick Cave, Pulp's Jarvis Cocker and Divine Comedy's Neil Hannon. In the last few years two U.K. groups, the Bathers and Cousteau, have emerged that owe deep debts to Scott. (There's also Scott 4, a band that went so far as to name itself after one of Walker's solo albums.)

Ohio-born Walker began is career in the late 1950s as Scotty Engel, cutting his teeth on teen-targeted tracks that went nowhere. Eventually, he joined forces with fellow Yanks Gary Leeds and John Maus to form the Walker Brothers. Settling in Britain during the Swinging '60s, the group recorded three albums of Phil Spector-esque ballads, two of which, "The Sun Ain't Gonna Shine Anymore" and "Make It Easy on Yourself," proved to be massively successful on both sides of the Atlantic. But as pyschedelia took hold, the Walker Brothers' sound quickly dated, and the mercurial Scott left his Brothers. But who would've anticipated the subtlety and seriousness of what came next?

With "Scott" (released in 1967), Walker debuted a fresh sound - cool, lush and haunting. Combining Tin Pan Alley balladry, German cabaret and the vocal styling of Jack Jones (Walker's admitted favorite) with sophisticated orchestral arrangements, Walker's new direction was decidedly not about flower power, communal love or dropping acid. Coupled with the tunes of French composer Jacques Brel as well as his own cryptic but melodious ruminations, the album was both groundbreaking and artistically accomplished. Although it went unnoticed in the United States, Scott topped the charts in his adopted homeland, where his celebrity, despite Walker's reticence, showed no signs of abating.

Listening to "Scott" now, you have to wonder what was at the root of Walker's mass appeal. Pitted against seemingly MOR-sounding songs, his peculiar lyrics - sung in a peerless, incorporeal baritone - project desire and despair, as in the eerie "Montague Terrace (In Blue)": "His bloated belching figure stomps/He may crash through the ceiling soon/The window sees trees cry from the cold/And claw the moon." In the brooding "Such a Small Love," Walker's words recall W.H. Auden's: "Mist falls and his voice cracks from the morning/Flowers and my body feels like lead/Someone should have stopped the birds from singing today/Hammers from striking nails into clay." It's hard to imagine today's Top 40 emphasizing songs that delve into such complex and weighty matters.

"Scott 2" mined much the same vein as the first album, with Walker interspersing Brel numbers like "Next" and "Jackie" in between his own increasingly mature compositions. In "The Bridge," he mulls morosely the passing of a prostitute with truly poetic lyrics: "At night the people's faces danced/Like pearls colliding on the breast/Of fat Marie whose thunder laugh/Was just a thread from crying."

This enigmatic ambiance continued on "Scott 3," which contains what is arguably Walker's finest composition, "It's Raining Today." Against dissonant strings and a gentle acoustic guitar, Walker wraps his liquid voice around the wistful tale of a chance encounter: "It's raining today/and I'm just about to forget the train window girl/That wonderful day we met/She smiles through the smoke from my cigarette." With its terrible beauty, the musical setting of the song is extraordinarily evocative, its impact undeniable.

The last record of this ambitious series, 1969's "Scott 4," was entirely self-penned. As a cohesive collection, it is possibly his finest moment. A less bombastic affair with traces of soul, folk and country, the album was even more introspective than his previous work. Certainly, he could not be matched for out-of-leftfield subject matter. Walker grafted an Ennio Morricone-style arrangement onto "The Seventh Seal," a song based on the classic film by Ingmar Bergman in which a knight plays a game of chess with Death. Then there's "The Old Man Is Back Again," an ode to Josef Stalin. On "Boy Child," Walker cuts to what for him is clearly an emotional truth: "You'll lose your way/A boy child rides upon your back/Take him away/Through mirrors dark and blessed with cracks/Through forgotten courtyards/Where you used to search for youth."

Curiously, at the height of Walker's commerical success, "Scott 4" was sales disappointment, falling quickly off the charts and into the cutout bin - a failure that led Walker to lean more toward outside songwriters for his next few releases, which were much less interesting and innovative.

During the 1970s, Scott and his fellow Walker Brothers reunited for three records that, with the exception of band-composed "Nite Flights," failed to realize a more mature sound and image for the group. It wasn't until 1984 that Scott finally released a new album of original material. Although not a breakthrough on the charts, "Climate of Hunter" was, nonetheless, a compelling, minimalist delight. Its unsettled, abstract quality was more fully realized on his next disc, "Tilt" (released in the U.K. in 1995 and issued in America two years later). Part industrial, part tone poem, part God-knows-what, it's angular and difficult, more about sensation than sense. In "Bouncer See Bouncer," Walker muses in a glutinous voice: "The riff with the swaddling hair/Those sisters who never broke us/The link missing at the rear/and the halo, halo of locusts." With its insect-buzzing percussion and harsh elegance, "Tilt" has no obvious reference points. Call it uneasy listening music.

Walker continues to release material in dribs and drabs; in 1999 he contributed a song to the James Bond flick "The World Is Not Enough" and composed the soundtrack to an obscure French film, "Pola X." Just last year, he wrote and produced a tune on Ute Lemper's CD, "Punishing Kiss," as well as handling the production chores on Pulp's "We Love Life."

Even with the surge of interest in artists like Burt Bacharach and Tony Bennett and the whole loungecore movement, it's unlikely that Walker will ever be more than a cult figure. It's doubtful he cares one way or the other. In recent interviews, Scott professed an interest in involving himself only in pursuits that hold actual meaning for him, like painting.

Perhaps the quote by Albert Camus from the liner of "Scott 3" best expresses the temperament of Scott Walker: "A man's work is nothing but this slow trek to discover through the detours of his art, those two or three great and simple images in whose presence his heart first opened."